RDU has one of few full body scanners

After investigators say a 23-year-old Nigerian man tried to bring down a Northwest flight from Amsterdam to Detroit, there's a heightened interest in airport security.

The Obama administration has ordered investigations into the two areas of aviation security -- how travelers are placed on watch lists and how passengers are screened -- as critics questioned how Umar Farouk Abdulmutallab was allowed to board the Dec. 25 flight.

Investigators say Abdulmutallab had a small bag holding a potentially deadly concoction of liquid and powder explosive material tucked below his waist. Instead of detonating, the device burst into flames and the 23-year-old was subdued by other passengers.

Billions of dollars have been spent on aviation security since the Sept. 11, 2001, terrorist attacks, when commercial airliners were hijacked and used as weapons. Much of that money has gone toward training and equipment that some security experts say could have detected the explosive device that Abdulmutallab allegedly used.

But there are only 40 full body scanners in use at airports across the U.S. One is at Raleigh Durham International.

The machines are called Millimeter Wave Scanners. They emit radio waves that transmit a picture that looks like a grey version of the person scanned. A viewer can see through clothes to what's hidden beneath.

The image can get so detailed that privacy groups have successfully lobbied for a series of protections to be put in place to protect the person being scanned.

There are two machine operators. One only sees the passenger. The other only sees the image. Passenger's facial features are blurred, along with sensitive areas and the images aren't saved or stored.

Finally, a passenger can opt out of going through the machine. They instead get a pat down. But while some privacy advocates still aren't satisfied with those protections, folks who spoke with ABC11 Eyewitness News at RDU Monday said they'd like to see the machine made mandatory.

"I feel everyone should go through that, because our country is at such a point right now where we need absolute security, you know?" offered traveler Collin Clingerman.

"I don't think of it as invasive in any way or a naked scan. I think of it as a safety factor," said traveler Dorcia Chaison.

Some have worried about health issues, but experts say the machines put out a fraction of the radio energy of a common cell phone.

Leading lawmakers - including senators Arlen Specter of Pennsylvania and Joe Lieberman of Connecticut - are calling for wider use of the machines.